What Is Biological Systematics?
It is customary to define scientific disciplines through their subject areas by indicating what exactly they study: physics, chemistry, biology, geography, linguistics, etc. Within each of these domains of knowledge, sub-areas are distinguished on a similar basis: microphysics and cosmology, economical and physical geography, histology and embryology, etc. It can be reasonably assumed that this general principle is true for biological systematics.
As can be seen from the previous section, systematics, if considered natural-philosophically, is associated with exploration of the System of Living Nature, with its ultimate end being elaboration of the Natural System or, more correctly, natural classification representing it in some way. From a quite empirical standpoint, systematics is defined as a branch of biology studying diversity of organisms (biological diversity, aka biodiversity) in all and any of its manifestations, representing the results of the study in the form of some “omnispective” classifications as a kind of reference system [Blackwelder 1967]. Both treatments, despite a significant difference in their backgrounds, are too broad: it turns out that systematics is the science of biological diversity “in general” and, accordingly, should be rightfully called biosystematics (in fact it is sometimes defined and called this way). In this case, what about ecology or biogeography also dealing with the same biodiversity, though in their own manner? On the other hand, there are significantly narrower definitions of systematics, based on their particular backgrounds: for example, it is defined sometimes as a “science of species” [Mayr 1969; Wheeler 2009]. In this case, a question arises: what about the supraspecific taxa? Does not and should not systematics study them?
From this, it becomes clear that the definition of systematics as a scientific discipline through the definition of its subject area is not an easy task. To say that it studies the System of Living Nature “in general” or biodiversity “in general” is too vague. But it is too narrow to associate it with some particular task (as in the case of the study of species). Systematics is actually a branch of biology studying the diversity of organisms and elaborating classifications to represent it in one way or another—but what kind of biodiversity does it actually deal with?
Taking all the above considerations into account and not going more deeply into this issue, it seems correct enough, from a theoretical perspective, to treat systematics as a branch of biology that develops:
- • specific ways of understanding the System of Living Nature (typological, phylogenetic, organismic, etc.) as particular manifestations (aspects) of the ordered diversity of organisms
- • the methods and criteria by which specific classifications can be elaborated within the contexts of those particular understandings
- • the classifications that might be treated as natural with respect to those particular understandings.
The Structure of Systematics
A well-thought-out “stratification” of systematics as a scientific discipline should, first of all, provide for the delineation of its main divisions. What exactly and how exactly should be reflected in classifications, how' they should be elaborated, by which criteria they could be considered natural—these fundamental questions are posed and answers sought for by the theoretical division of systematics. Various kinds of theoretical propositions are implemented in specific classifications by its practical division. Finally, methods of bringing such classifications into the forms suitable for use by other disciplines are being developed by the applied division of systematics.
Theoretical systematics was denoted as taxonomy by the botanist Augustin Pyramus de Candolle at the beginning of the 18th century [de Candolle 1819]; another recent designation is taxonology [Zuev 2015]. This understanding of taxonomy is most widely accepted in contemporary literature, but there are other interpretations of it. Some authors identify taxonomy with the entire systematics [Mayr 1942; Rogers 1958; Griffiths 1974a,b; Zuev 2015]. Others call taxonomy the practical issues dealing with the identification of particular taxa [Blackwelder and Boyden 1952; Blackwelder 1967; Wheeler 2001].
Considering understanding of possible meanings of taxonomy as dealing basically with theoretical knowledge, it makes sense to distinguish between its two principal levels, universal and biological [Wilkins 1998; Zuev 2015]. Universal taxonomy develops general principles of classificatory activity and can be considered a part of logic; it is nearly the same as “philosophical” taxonomy [Humberstone 1996], or classiology [Kozhara 2006; Pokrovsky 2014], or “the doctrine of any classifications” [Meyen and Schreider 1976]. Biological taxonomy is a special subject branch of universal taxonomy that shapes the theoretical section of biological systematics.
The most important and most general task of biological taxonomy is the development of the philosophical and theoretical foundations of biological systematics. The whole of this book is devoted to these foundations from which one can conclude that this objective is very extensive and multifaceted. Specifying this objective the following most significant points are to be indicated.
The first point, in both order and importance, in that general task is the development of the cognitive situation in which systematics operates, and within which framework the basic onto-epistemic foundations of this discipline are developed. As a matter of fact, the construction of the entire edifice of systematics as a scientific discipline begins with setting and solving theoretical problems within the framework of this principal point. Obviously, they are based on the general principles of the philosophy of science, so establishing certain “contacts” with the latter is also an important task of the taxonomy. According to the structure of the cognitive situation, the following two main groups of more particular tasks should be distinguished here:
- • the ontology of systematics deals with the correct definition of the subject area of taxonomy, that is, what it studies; herewith, it is defined rather informally as taxonomic diversity’ (TD: see below)
- • the epistemology of systematics deals with developing principles of systematic research, that is, how to investigate the subject area thus defined; one of the aims of this is a validation of the scientific status of taxonomic knowledge developed by systematics.
The second point is the development of taxonomic theory’, which constitutes the main content of theoretical knowledge in systematics. It has a rather complex structure: general and particular theories are distinguished in it; the latter are divided according to the principles of both delineating their particular subject areas and elaborating methods of their exploration.
A correct delineation of the research programs in systematics is closely related to the previous task. They (at least some of them) are sometimes called “schools,” “theories,” or even “philosophies” of systematics. In the understanding accepted here, these programs serve as a means of implementing particular taxonomic theories. Each of them actualizes and implements general theoretical concepts in its own way and brings them to an operational state suitable for use in the practice of taxonomic research.
Another key point of taxonomy, which no scientific discipline can do without, is the development of its conceptual apparatus (thesaurus). The matter is that the System of Nature (in any meaning) is given not in personal perceptions but in general concepts and notions, including definitions of the subject area, classification, taxon, character, homology, etc. Therefore, this thesaurus shapes the entire cognitive situation of systematics, in which particular taxonomic research is conducted.
Finally, as the modern philosophy of science stresses a close connection between history and theory of science, one of the specific tasks of taxonomy is the reconstruction of the conceptual history of systematics [Pavlinov 2018]. This allows one to find out how changes in the philosophical, general scientific, and even socio-cultural contexts yield corresponding changes in theoretical foundations of systematics in the course of its historical development.
Practical systematics implements the ideas elaborated by taxonomic theories. These theories form the context of empirical systematic studies, serving as a prerequisite for setting their tasks, methods, choice of characters, ways of representing the structure of TD, etc. Empiricists are unlikely to agree with such an assessment of the relations between theoretical and empirical aspects of systematics: for them, practical systematics is self-sufficient and shapes the basis of this discipline. And nevertheless, it is quite proper to emphasize here that, according to the modern philosophy of science, empirical taxonomic knowledge is meaningless outside a certain biologically sound theoretical knowledge.
According to this, practical taxonomic research starts with bringing theoretical ideas to the point where they can be applied in the procedures of elaborating particular classifications. For example, in phylogenetic systematics, this includes specific definitions and methods of assessing similarity and kinship, choosing characters as indicators of the latter, methods of reconstructing phylogenetic history, and, finally, ways of presenting the results of this history in the form of phylogenetic classifications.
This is not a practice yet, but rather (if it may so called) a “semi-theory.” The main practical task is to develop specific classifications and present them in a format that makes them available for further use. This general task is deconstructed into the following components:
- • conducting particular taxonomic research, including revision of existing and development of new classifications, with the descriptions of new taxa and “closure” of those not confirmed by new research
- • elaboration of identification keys that allow particular organisms to be allocated to particular taxa
- • publication of the results of this research (classifications and keys) in articles or monographs.
One of important tasks of practical systematics is the elaboration and application of taxonomic nomenclature dealing with the regulations and manipulations of scientific names of taxa. It is governed by a number of codes in botany, zoology, etc. [Jeffrey 1992; Pavlinov 2015].
Another important task of practical systematics the development of its empirical basis in the form of scientific systematic collections. Systematics was and remains a “museum” science; this is its fundamental specificity. The reason is that collections, in their epistemic status, are analogous to standard experiments in physics and chemistry: they provide both repeatability and, thereby, testability of taxonomic knowledge, making it scientific. Therefore systematics cannot do without its collections, just like physics or chemistry cannot do without their experiments [Whewell 1847;Mayr 1982; Pavlinov 2016]. Long-existing scientific collections kept under standard conditions represent one of the key information resources for research on the structure of biodiversity [Miller 1985, 1993; Graham et al. 2004; Berendsohn 2007; Arino 2010; Drew 2011]. Therefore, systematics must develop systematic collections, as physics and chemistry develop their experimental base. The strategy of collections development is determined by the fact that the general structure of the global collection pool should be adequate to the diversity of organisms studied by systematics (Cotterill 2002 2016; Pavlinov 2016).
One of the very important tasks of practical systematics is specific pedagogical activity: it is called on to ensure the reproduction of the taxonomic community to conduct taxonomic research in different groups of organisms. No science can do without it; in systematics, ensuring a continuous “relay” of transfer of practical knowledge about the diversity of organisms between generations is of crucial importance. The reason is that such knowledge is largely descriptive; it contains a large portion of accumulated experience regarding particular groups of organisms and methods of their research. And no one theory, however perfect and detailed, can replace such experience: its loss means, in fact, that a certain group of organisms “falls out” of the sphere of taxonomic research.
Applied systematics provides a junction between systematics proper and all those spheres of human activity that involve contact with biological diversity. It is based on the results of practical systematics, and its main task is information support of that activity.